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Scientific poster presentations

Posters

Date: Monday, March 7th, 2016; Start Time: (Slot # 2);
Session: SafetyAbstract:
12 full and 4 associate partners from all over Europe (renowned universities, research institutes and industry) have trained a total of 15 Early Stage Researchers within the Marie Curie Training Network PIMMS during the past four years. PIMMS has focused on the application of PTR-MS to four key areas: environmental, food and health sciences and homeland security. Here we present work on one of the successful projects within PIMMS: the analysis of New Psychoactive Substances (NPS), i.e. compounds that do not belong to the common group of illicit drugs (e.g. cocaine, ecstasy, LSD, etc.) but mimic their intoxicating effects. Utilizing a high-resolution and high-sensitivity PTR-TOF 8000 (PTR-MS instrument equipped with a time-of-flight mass analyzer and switchable reagent ions capability) we studied the reduced electric field dependence of the reactions of a wide selection of NPS with the reagent ions H3O+, NO+, O2+ and Kr+.

We present an overview of these results and highlight key findings, and in particular the interesting results we obtained for the popular NPS ethylphenidate (EPH, C15H21NO2), a drug closely related to the prescription drug methylphenidate, better known as Ritalin. Over a period of three years we purchased a total of six EPH samples via the Internet. All samples contained the advertised active ingredient EPH and some impurities, which could be assigned to residuals from the synthesis process, as illustrated in the figure below, which shows the product ions originating from various samples (those from EPH marked with an E). Although purchased from the same vendor, we found that the impurities differed between batches, indicating that different routes of synthesis had been used in the production processes.
PIMMS is supported by the EC 7th Framework Programme (GA 287382). WJA received a BBSRC-Industrial CASE studentship.

Date: Thursday, March 10th, 2016; Start Time: (Slot # 2);
Session: Application of Mass SpectrometryAbstract:
PTR-MS is a well-established direct injection trace gas analysis method with various advantages: high sensitivity, low detection limits, no sample preparation and online quantification. The latter is possible because of well-known conditions in the PTR drift tube and particularly simple because of low fragmentation caused by the chemical ionization via H3O+. However, especially when quadrupole mass spectrometer based PTR-MS instruments are used (instead of high mass resolution TOF analyzers), overlaps of product ions (protonated parent and fragment ions) may occur and make data evaluation somewhat complicated.

Recently, we have published a series of studies which demonstrate that by changing the ionization conditions, such as the reduced electric field strength in the PTR drift tube (E/N) or by switching the reagent ions (SRI) from H3O+ to NO+ or O2+, respectively, the selectivity of a PTR-MS instrument can be considerably increased. Stimulated by these results we have developed a new software tool, "Automated Measurement and Evaluation” (AME), which performes measurements at various ionization conditions and subsequently processes the data with real-time output. We demonstrate this process using several examples. For instance, isopropyl alcohol and acetic acid, two isobaric compounds, are both detected at m/z 61 (protonated parent) and m/z 43 (fragment) in PTR-MS, which hinders identification and quantification. Using a substance library containing the fragmentation ratios of both compounds at different E/N levels in combination with an ordinary least squares (OLS) model, the AME software separates and quantifies the two isobars independently. Additionally, AME also averages the data, to reduce noise, exports and displays the processed data. All these features have been implemented with industrial monitoring applications in mind, where an automated process is required.